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<FONT color="green">001</FONT>    package org.codemonkey.swiftsocketserver;<a name="line.1"></a>
<FONT color="green">002</FONT>    <a name="line.2"></a>
<FONT color="green">003</FONT>    import java.io.IOException;<a name="line.3"></a>
<FONT color="green">004</FONT>    import java.net.DatagramPacket;<a name="line.4"></a>
<FONT color="green">005</FONT>    import java.net.DatagramSocket;<a name="line.5"></a>
<FONT color="green">006</FONT>    import java.net.ServerSocket;<a name="line.6"></a>
<FONT color="green">007</FONT>    import java.net.Socket;<a name="line.7"></a>
<FONT color="green">008</FONT>    import java.net.SocketAddress;<a name="line.8"></a>
<FONT color="green">009</FONT>    import java.util.ArrayList;<a name="line.9"></a>
<FONT color="green">010</FONT>    import java.util.HashMap;<a name="line.10"></a>
<FONT color="green">011</FONT>    import java.util.List;<a name="line.11"></a>
<FONT color="green">012</FONT>    import java.util.Map;<a name="line.12"></a>
<FONT color="green">013</FONT>    <a name="line.13"></a>
<FONT color="green">014</FONT>    import org.apache.log4j.Logger;<a name="line.14"></a>
<FONT color="green">015</FONT>    <a name="line.15"></a>
<FONT color="green">016</FONT>    /**<a name="line.16"></a>
<FONT color="green">017</FONT>     * Abstraction of the server socket. Acts as a wrapper for {@link ServerSocket} and {@link DatagramSocket} to provide uniform behavior.<a name="line.17"></a>
<FONT color="green">018</FONT>     * <a name="line.18"></a>
<FONT color="green">019</FONT>     * @author Benny Bottema<a name="line.19"></a>
<FONT color="green">020</FONT>     * @see ServerEndpointTCP<a name="line.20"></a>
<FONT color="green">021</FONT>     * @see ServerEndpointUDP<a name="line.21"></a>
<FONT color="green">022</FONT>     * @since 1.0<a name="line.22"></a>
<FONT color="green">023</FONT>     */<a name="line.23"></a>
<FONT color="green">024</FONT>    abstract class ServerEndpoint {<a name="line.24"></a>
<FONT color="green">025</FONT>    <a name="line.25"></a>
<FONT color="green">026</FONT>            /**<a name="line.26"></a>
<FONT color="green">027</FONT>             * All subclasses use the logger anchored to &lt;code&gt;ServerEndpoint.class&lt;/code&gt;.<a name="line.27"></a>
<FONT color="green">028</FONT>             */<a name="line.28"></a>
<FONT color="green">029</FONT>            protected static final Logger LOGGER = Logger.getLogger(ServerEndpoint.class);<a name="line.29"></a>
<FONT color="green">030</FONT>    <a name="line.30"></a>
<FONT color="green">031</FONT>            /**<a name="line.31"></a>
<FONT color="green">032</FONT>             * @return An endpoint that acts similarly for TCP and UDP clients.<a name="line.32"></a>
<FONT color="green">033</FONT>             * @throws IOException Thrown by {@link ServerEndpointTCP#getClientEndpoint()}<a name="line.33"></a>
<FONT color="green">034</FONT>             */<a name="line.34"></a>
<FONT color="green">035</FONT>            abstract ClientEndpoint getClientEndpoint()<a name="line.35"></a>
<FONT color="green">036</FONT>                            throws IOException;<a name="line.36"></a>
<FONT color="green">037</FONT>    <a name="line.37"></a>
<FONT color="green">038</FONT>            /**<a name="line.38"></a>
<FONT color="green">039</FONT>             * @return Whether an explicitly call has been made to {@link ServerEndpoint#close()} or close on the passed in socket (both TCP and<a name="line.39"></a>
<FONT color="green">040</FONT>             *         UDP).<a name="line.40"></a>
<FONT color="green">041</FONT>             */<a name="line.41"></a>
<FONT color="green">042</FONT>            abstract boolean isClosed();<a name="line.42"></a>
<FONT color="green">043</FONT>    <a name="line.43"></a>
<FONT color="green">044</FONT>            /**<a name="line.44"></a>
<FONT color="green">045</FONT>             * Call the close method on the embedded socket (works for both TCP and UDP).<a name="line.45"></a>
<FONT color="green">046</FONT>             * <a name="line.46"></a>
<FONT color="green">047</FONT>             * @throws IOException Thrown by {@link ServerEndpointTCP#close()}<a name="line.47"></a>
<FONT color="green">048</FONT>             */<a name="line.48"></a>
<FONT color="green">049</FONT>            abstract void close()<a name="line.49"></a>
<FONT color="green">050</FONT>                            throws IOException;<a name="line.50"></a>
<FONT color="green">051</FONT>    }<a name="line.51"></a>
<FONT color="green">052</FONT>    <a name="line.52"></a>
<FONT color="green">053</FONT>    /**<a name="line.53"></a>
<FONT color="green">054</FONT>     * Wrapper that delegates all calls directly to the decorated {@link ServerSocket}. The Server Endpoint abstraction mimics how TCP deals<a name="line.54"></a>
<FONT color="green">055</FONT>     * with clients and so the TCP server endpoint variant adds no extra functionality, except that it returns client endpoints instead of<a name="line.55"></a>
<FONT color="green">056</FONT>     * {@link Socket} instances (see {@link #getClientEndpoint()}.<a name="line.56"></a>
<FONT color="green">057</FONT>     * <a name="line.57"></a>
<FONT color="green">058</FONT>     * @author Benny Bottema<a name="line.58"></a>
<FONT color="green">059</FONT>     * @since 1.0<a name="line.59"></a>
<FONT color="green">060</FONT>     */<a name="line.60"></a>
<FONT color="green">061</FONT>    class ServerEndpointTCP extends ServerEndpoint {<a name="line.61"></a>
<FONT color="green">062</FONT>    <a name="line.62"></a>
<FONT color="green">063</FONT>            private final ServerSocket serverSocket;<a name="line.63"></a>
<FONT color="green">064</FONT>    <a name="line.64"></a>
<FONT color="green">065</FONT>            /**<a name="line.65"></a>
<FONT color="green">066</FONT>             * Constructor; simply stores a reference to the server socket.<a name="line.66"></a>
<FONT color="green">067</FONT>             * <a name="line.67"></a>
<FONT color="green">068</FONT>             * @param serverSocket The {@link ServerSocket} on which we connect new clients.<a name="line.68"></a>
<FONT color="green">069</FONT>             */<a name="line.69"></a>
<FONT color="green">070</FONT>            public ServerEndpointTCP(final ServerSocket serverSocket) {<a name="line.70"></a>
<FONT color="green">071</FONT>                    this.serverSocket = serverSocket;<a name="line.71"></a>
<FONT color="green">072</FONT>            }<a name="line.72"></a>
<FONT color="green">073</FONT>    <a name="line.73"></a>
<FONT color="green">074</FONT>            /**<a name="line.74"></a>
<FONT color="green">075</FONT>             * Returns a new {@link ClientEndpointTCP} {@link Socket} decorator (received from {@link ServerSocket#accept()}).<a name="line.75"></a>
<FONT color="green">076</FONT>             */<a name="line.76"></a>
<FONT color="green">077</FONT>            @Override<a name="line.77"></a>
<FONT color="green">078</FONT>            ClientEndpoint getClientEndpoint()<a name="line.78"></a>
<FONT color="green">079</FONT>                            throws IOException {<a name="line.79"></a>
<FONT color="green">080</FONT>                    return new ClientEndpointTCP(serverSocket.accept());<a name="line.80"></a>
<FONT color="green">081</FONT>            }<a name="line.81"></a>
<FONT color="green">082</FONT>    <a name="line.82"></a>
<FONT color="green">083</FONT>            /**<a name="line.83"></a>
<FONT color="green">084</FONT>             * @return {@link ServerSocket#isClosed()}<a name="line.84"></a>
<FONT color="green">085</FONT>             */<a name="line.85"></a>
<FONT color="green">086</FONT>            @Override<a name="line.86"></a>
<FONT color="green">087</FONT>            boolean isClosed() {<a name="line.87"></a>
<FONT color="green">088</FONT>                    return serverSocket.isClosed();<a name="line.88"></a>
<FONT color="green">089</FONT>            }<a name="line.89"></a>
<FONT color="green">090</FONT>    <a name="line.90"></a>
<FONT color="green">091</FONT>            /**<a name="line.91"></a>
<FONT color="green">092</FONT>             * Calls {@link ServerSocket#close()}<a name="line.92"></a>
<FONT color="green">093</FONT>             */<a name="line.93"></a>
<FONT color="green">094</FONT>            @Override<a name="line.94"></a>
<FONT color="green">095</FONT>            void close()<a name="line.95"></a>
<FONT color="green">096</FONT>                            throws IOException {<a name="line.96"></a>
<FONT color="green">097</FONT>                    serverSocket.close();<a name="line.97"></a>
<FONT color="green">098</FONT>            }<a name="line.98"></a>
<FONT color="green">099</FONT>    }<a name="line.99"></a>
<FONT color="green">100</FONT>    <a name="line.100"></a>
<FONT color="green">101</FONT>    /**<a name="line.101"></a>
<FONT color="green">102</FONT>     * Wrapper that adds TCP like client handling to the UDP {@link DatagramSocket}.<a name="line.102"></a>
<FONT color="green">103</FONT>     * <a name="line.103"></a>
<FONT color="green">104</FONT>     * @author Benny Bottema<a name="line.104"></a>
<FONT color="green">105</FONT>     * @see #ServerEndpointUDP<a name="line.105"></a>
<FONT color="green">106</FONT>     * @see #getClientEndpoint<a name="line.106"></a>
<FONT color="green">107</FONT>     * @see DatagramPacketReceiver<a name="line.107"></a>
<FONT color="green">108</FONT>     * @since 1.0<a name="line.108"></a>
<FONT color="green">109</FONT>     */<a name="line.109"></a>
<FONT color="green">110</FONT>    class ServerEndpointUDP extends ServerEndpoint {<a name="line.110"></a>
<FONT color="green">111</FONT>    <a name="line.111"></a>
<FONT color="green">112</FONT>            /**<a name="line.112"></a>
<FONT color="green">113</FONT>             * This should probably be tuned at some point to allow for larger datagram packets.<a name="line.113"></a>
<FONT color="green">114</FONT>             */<a name="line.114"></a>
<FONT color="green">115</FONT>            private static final int PACKET_BUFFER_SIZE = 1024;<a name="line.115"></a>
<FONT color="green">116</FONT>    <a name="line.116"></a>
<FONT color="green">117</FONT>            /**<a name="line.117"></a>
<FONT color="green">118</FONT>             * The server socket we're accepting client messages on in the form of UDP datagram packets.<a name="line.118"></a>
<FONT color="green">119</FONT>             */<a name="line.119"></a>
<FONT color="green">120</FONT>            private final DatagramSocket datagramSocket;<a name="line.120"></a>
<FONT color="green">121</FONT>    <a name="line.121"></a>
<FONT color="green">122</FONT>            /**<a name="line.122"></a>
<FONT color="green">123</FONT>             * The list of known clients, based on the {@link SocketAddress} of previously received {@link DatagramPacket} objects.<a name="line.123"></a>
<FONT color="green">124</FONT>             */<a name="line.124"></a>
<FONT color="green">125</FONT>            private final Map&lt;SocketAddress, ClientEndpointUDP&gt; knownClients;<a name="line.125"></a>
<FONT color="green">126</FONT>    <a name="line.126"></a>
<FONT color="green">127</FONT>            /**<a name="line.127"></a>
<FONT color="green">128</FONT>             * The list of new clients ready to be returned when asked for a new client endpoint.<a name="line.128"></a>
<FONT color="green">129</FONT>             */<a name="line.129"></a>
<FONT color="green">130</FONT>            private final List&lt;ClientEndpointUDP&gt; newClients;<a name="line.130"></a>
<FONT color="green">131</FONT>    <a name="line.131"></a>
<FONT color="green">132</FONT>            /**<a name="line.132"></a>
<FONT color="green">133</FONT>             * Constructor; starts a new &lt;code&gt;Thread&lt;/code&gt; listening for new datagram packets. If a new client sends a message, it will be<a name="line.133"></a>
<FONT color="green">134</FONT>             * returned on {@link #getClientEndpoint()}. In either case the datagram is passed on to the client endpoint being enqueued.<a name="line.134"></a>
<FONT color="green">135</FONT>             * <a name="line.135"></a>
<FONT color="green">136</FONT>             * @param datagramSocket A DatagramSocket to listen to UDP messages.<a name="line.136"></a>
<FONT color="green">137</FONT>             */<a name="line.137"></a>
<FONT color="green">138</FONT>            public ServerEndpointUDP(final DatagramSocket datagramSocket) {<a name="line.138"></a>
<FONT color="green">139</FONT>                    this.datagramSocket = datagramSocket;<a name="line.139"></a>
<FONT color="green">140</FONT>                    knownClients = new HashMap&lt;SocketAddress, ClientEndpointUDP&gt;();<a name="line.140"></a>
<FONT color="green">141</FONT>                    newClients = new ArrayList&lt;ClientEndpointUDP&gt;();<a name="line.141"></a>
<FONT color="green">142</FONT>                    new Thread(new DatagramPacketReceiver()).start();<a name="line.142"></a>
<FONT color="green">143</FONT>            }<a name="line.143"></a>
<FONT color="green">144</FONT>    <a name="line.144"></a>
<FONT color="green">145</FONT>            /**<a name="line.145"></a>
<FONT color="green">146</FONT>             * Returns a new client endpoint in case a datagram packet is received from an unknown client. Otherwise, nothing is returning and this<a name="line.146"></a>
<FONT color="green">147</FONT>             * method remains blocking (like {@link ServerSocket#accept()}) until a new client sends a datagram packet.<a name="line.147"></a>
<FONT color="green">148</FONT>             * &lt;p&gt;<a name="line.148"></a>
<FONT color="green">149</FONT>             * TCP messages received are inherently coupled to a (client) &lt;code&gt;Socket&lt;/code&gt;. To mimic this behavior {@link ServerEndpointUDP}<a name="line.149"></a>
<FONT color="green">150</FONT>             * keeps track of known clients (by having received datapackets from them before) and when receiving new datagram packets, we'll try to<a name="line.150"></a>
<FONT color="green">151</FONT>             * match the sender address to a known client. Once matched, we let the associated client endpoint deal with the datagram packet, as a<a name="line.151"></a>
<FONT color="green">152</FONT>             * TCP Socket would have done. If the datagram packet could not be matched to a known client, a new client is trying to communicate with<a name="line.152"></a>
<FONT color="green">153</FONT>             * us, and so we can return a new &lt;code&gt;ClientEndpoint&lt;/code&gt;.<a name="line.153"></a>
<FONT color="green">154</FONT>             */<a name="line.154"></a>
<FONT color="green">155</FONT>            @Override<a name="line.155"></a>
<FONT color="green">156</FONT>            ClientEndpoint getClientEndpoint() {<a name="line.156"></a>
<FONT color="green">157</FONT>                    while (newClients.isEmpty() &amp;&amp; !datagramSocket.isClosed()) {<a name="line.157"></a>
<FONT color="green">158</FONT>                            ServerUtil.defaultSleep();<a name="line.158"></a>
<FONT color="green">159</FONT>                    }<a name="line.159"></a>
<FONT color="green">160</FONT>                    if (newClients.size() &gt; 0) {<a name="line.160"></a>
<FONT color="green">161</FONT>                            return newClients.remove(0);<a name="line.161"></a>
<FONT color="green">162</FONT>                    } else {<a name="line.162"></a>
<FONT color="green">163</FONT>                            // socket.close() will be called when the SwiftSocketServer is stopping,<a name="line.163"></a>
<FONT color="green">164</FONT>                            // returning null won't cause NullPointerException in that case<a name="line.164"></a>
<FONT color="green">165</FONT>                            return null;<a name="line.165"></a>
<FONT color="green">166</FONT>                    }<a name="line.166"></a>
<FONT color="green">167</FONT>            }<a name="line.167"></a>
<FONT color="green">168</FONT>    <a name="line.168"></a>
<FONT color="green">169</FONT>            /**<a name="line.169"></a>
<FONT color="green">170</FONT>             * Receives {@link DatagramPacket} objects and delegates these to an {@link ClientEndpoint} to emulate TCP {@link Socket} behavior where<a name="line.170"></a>
<FONT color="green">171</FONT>             * a &lt;code&gt;Socket&lt;/code&gt; per client receives messages from a connected client.<a name="line.171"></a>
<FONT color="green">172</FONT>             * &lt;p&gt;<a name="line.172"></a>
<FONT color="green">173</FONT>             * By abstracting this behavior in 'client endpoints', we can now for both TCP Socket messages and datagram packets act as though the<a name="line.173"></a>
<FONT color="green">174</FONT>             * endpoint received it directly from a client and so have consistent and uniform behavior for handling TCP and UDP messages. The only<a name="line.174"></a>
<FONT color="green">175</FONT>             * downside to this is that we cannot detect a client dropping the connection (so PingPong mode is advised).<a name="line.175"></a>
<FONT color="green">176</FONT>             * <a name="line.176"></a>
<FONT color="green">177</FONT>             * @author Benny Bottema<a name="line.177"></a>
<FONT color="green">178</FONT>             * @since 1.0<a name="line.178"></a>
<FONT color="green">179</FONT>             */<a name="line.179"></a>
<FONT color="green">180</FONT>            private class DatagramPacketReceiver implements Runnable {<a name="line.180"></a>
<FONT color="green">181</FONT>                    @Override<a name="line.181"></a>
<FONT color="green">182</FONT>                    public void run() {<a name="line.182"></a>
<FONT color="green">183</FONT>                            // a DatagramSocket will only close if the server is stopping gracefully or a client time-out was detected using PingPong mode<a name="line.183"></a>
<FONT color="green">184</FONT>                            while (!datagramSocket.isClosed()) {<a name="line.184"></a>
<FONT color="green">185</FONT>                                    final DatagramPacket datagramPacket = new DatagramPacket(new byte[PACKET_BUFFER_SIZE], PACKET_BUFFER_SIZE);<a name="line.185"></a>
<FONT color="green">186</FONT>                                    try {<a name="line.186"></a>
<FONT color="green">187</FONT>                                            datagramSocket.receive(datagramPacket);<a name="line.187"></a>
<FONT color="green">188</FONT>                                    } catch (final IOException e) {<a name="line.188"></a>
<FONT color="green">189</FONT>                                            LOGGER.error("error waiting for new datagram packet in UDP server endpoint", e);<a name="line.189"></a>
<FONT color="green">190</FONT>                                            continue; // should we continue? if we don't we'll have a complete server crash on our hands<a name="line.190"></a>
<FONT color="green">191</FONT>                                    }<a name="line.191"></a>
<FONT color="green">192</FONT>                                    synchronized (knownClients) {<a name="line.192"></a>
<FONT color="green">193</FONT>                                            if (!knownClients.containsKey(datagramPacket.getSocketAddress())) {<a name="line.193"></a>
<FONT color="green">194</FONT>                                                    LOGGER.debug(String.format("received UDP datagram packet from unknown client endpoint [%s]",<a name="line.194"></a>
<FONT color="green">195</FONT>                                                                    datagramPacket.getSocketAddress()));<a name="line.195"></a>
<FONT color="green">196</FONT>                                                    final ClientEndpointUDP clientEndpoint = new ClientEndpointUDP(ServerEndpointUDP.this, datagramSocket,<a name="line.196"></a>
<FONT color="green">197</FONT>                                                                    datagramPacket);<a name="line.197"></a>
<FONT color="green">198</FONT>                                                    knownClients.put(datagramPacket.getSocketAddress(), clientEndpoint);<a name="line.198"></a>
<FONT color="green">199</FONT>                                                    newClients.add(clientEndpoint);<a name="line.199"></a>
<FONT color="green">200</FONT>                                            } else {<a name="line.200"></a>
<FONT color="green">201</FONT>                                                    String debugMsg = "received UDP datagram packet from known client endpoint [%s]";<a name="line.201"></a>
<FONT color="green">202</FONT>                                                    LOGGER.debug(String.format(debugMsg, datagramPacket.getSocketAddress()));<a name="line.202"></a>
<FONT color="green">203</FONT>                                                    if (LOGGER.isTraceEnabled()) {<a name="line.203"></a>
<FONT color="green">204</FONT>                                                            String messageReceived = new String(datagramPacket.getData());<a name="line.204"></a>
<FONT color="green">205</FONT>                                                            String traceMsg = "datagram packet received from %s, message: %s";<a name="line.205"></a>
<FONT color="green">206</FONT>                                                            LOGGER.trace(String.format(traceMsg, datagramPacket.getSocketAddress(), messageReceived));<a name="line.206"></a>
<FONT color="green">207</FONT>                                                    }<a name="line.207"></a>
<FONT color="green">208</FONT>                                                    knownClients.get(datagramPacket.getSocketAddress()).handleDatagramPacket(datagramPacket);<a name="line.208"></a>
<FONT color="green">209</FONT>                                            }<a name="line.209"></a>
<FONT color="green">210</FONT>                                    }<a name="line.210"></a>
<FONT color="green">211</FONT>                            }<a name="line.211"></a>
<FONT color="green">212</FONT>                    }<a name="line.212"></a>
<FONT color="green">213</FONT>            }<a name="line.213"></a>
<FONT color="green">214</FONT>    <a name="line.214"></a>
<FONT color="green">215</FONT>            /**<a name="line.215"></a>
<FONT color="green">216</FONT>             * Removes a client from the list of known clients. Most likely because it was explicitly closed by calling<a name="line.216"></a>
<FONT color="green">217</FONT>             * {@link ClientEndpointUDP#close()}.<a name="line.217"></a>
<FONT color="green">218</FONT>             * <a name="line.218"></a>
<FONT color="green">219</FONT>             * @param clientSocketAddress The socket address which identifies the {@link ClientEndpointUDP} to be removed.<a name="line.219"></a>
<FONT color="green">220</FONT>             */<a name="line.220"></a>
<FONT color="green">221</FONT>            public void removeClient(final SocketAddress clientSocketAddress) {<a name="line.221"></a>
<FONT color="green">222</FONT>                    knownClients.remove(clientSocketAddress);<a name="line.222"></a>
<FONT color="green">223</FONT>            }<a name="line.223"></a>
<FONT color="green">224</FONT>    <a name="line.224"></a>
<FONT color="green">225</FONT>            /**<a name="line.225"></a>
<FONT color="green">226</FONT>             * Returns whether a client is known to this (UDP) server endpoint.<a name="line.226"></a>
<FONT color="green">227</FONT>             * <a name="line.227"></a>
<FONT color="green">228</FONT>             * @param clientSocketAddress The address by which the client is identified.<a name="line.228"></a>
<FONT color="green">229</FONT>             * @return Whether {@link #knownClients} contains the given socket address.<a name="line.229"></a>
<FONT color="green">230</FONT>             */<a name="line.230"></a>
<FONT color="green">231</FONT>            public boolean hasClient(final SocketAddress clientSocketAddress) {<a name="line.231"></a>
<FONT color="green">232</FONT>                    return knownClients.containsKey(clientSocketAddress);<a name="line.232"></a>
<FONT color="green">233</FONT>            }<a name="line.233"></a>
<FONT color="green">234</FONT>    <a name="line.234"></a>
<FONT color="green">235</FONT>            /**<a name="line.235"></a>
<FONT color="green">236</FONT>             * @return {@link DatagramSocket#isClosed()}<a name="line.236"></a>
<FONT color="green">237</FONT>             */<a name="line.237"></a>
<FONT color="green">238</FONT>            @Override<a name="line.238"></a>
<FONT color="green">239</FONT>            boolean isClosed() {<a name="line.239"></a>
<FONT color="green">240</FONT>                    return datagramSocket.isClosed();<a name="line.240"></a>
<FONT color="green">241</FONT>            }<a name="line.241"></a>
<FONT color="green">242</FONT>    <a name="line.242"></a>
<FONT color="green">243</FONT>            /**<a name="line.243"></a>
<FONT color="green">244</FONT>             * Calls {@link DatagramSocket#close()}<a name="line.244"></a>
<FONT color="green">245</FONT>             */<a name="line.245"></a>
<FONT color="green">246</FONT>            @Override<a name="line.246"></a>
<FONT color="green">247</FONT>            void close() {<a name="line.247"></a>
<FONT color="green">248</FONT>                    datagramSocket.close();<a name="line.248"></a>
<FONT color="green">249</FONT>            }<a name="line.249"></a>
<FONT color="green">250</FONT>    }<a name="line.250"></a>




























































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